Preparation of diacetyl with butter cultures



Patented Feb. '19, 1952 PREPARATION OF DIACETYL WITH BUTTER CULTURESMelvin Wayne Marcoux,

to Armour and Company, Chicago, iii, a corporation of Illinois Chicago,Ill., assignor No Drawing. Application June 21, 1941 Serial No. 756,337

Claims. (Cl. 99-140) This invention relates to the production ofdiacetyl with butter cultures consisting of a single tions which greatlyaccelerate the production of diacetyl. Other specific objects andadvantages will appear as the specification proceeds.

In one embodiment of my invention, pasteurized skimmed milk isinoculated with a single organism, such as, for example, Streptococcusdiacetylactis, and incubated at temperatures of from 75-80 F. Theincubation may be continued until the titratable acidity reachesOHS-0.80%.

I have discovered that excellent results are obtained when theincubation is carried on at 75-80 F. until a titratable acidity of 0.55%lactic acid is present. Then the material is cooled to about Gil-70 F.for the remainder of the ripening period. during which time thetitratable acidity reaches 0.75-0.80%.

By regular methods heretofore employed, it requires from 16 to 20 hoursto develop a fully ripened culture. By the above process, in which theinitial incubation temperature or ,a single species culture is raised tothe range described, the process can be completed within from .8 to 12hours.

In the proce above described, I prefer to pasteurize skimmed milk as thefirst step. I next add the single organism (about 1-5% inoculation). Iincubate at 75-80 F. until a titratable acidity of 0.55% lactic acid ispresent. As a final step, I cool the material to 68-70 F; or thereaboutsfor the remainder of the ripening period, during which time thetitratable acidity reaches 0.75-0.80%. During this final step thematerial is continually agitated to produce aeration and thereby oxidizeacetylmethyl carbinol to diacetyl.

The actual diacetyl production occurs during the final step and at thelower temperature. However, by the use of the elevated temperature inthe initial incubation step, it is possible to accelerate the process sothat from 5 to 6 hours can be saved in preparing a batch ofoleomargarine, for instance.

There are a number oi well-known single organisms which may be used forthe production of diacetyl. I have found that unusually good results arehad when using Streptococcus diacetulactis. which formsacetylmethylcarbinol from citric acid of the milk. The microorganismStreptococcus diacetplactis is deposited with the American Type CultureCollection. Washington, D. C., and has been assigned the accessionnumber 11007 by that depository.

In carrying out the modification of the process in which the coolingstep is not employed, the pasteurized skimmed milk, partially skimmedmilk or whole milk is inoculated with the single organism and thetemperature raised to IS-80 F., agitation being employed throughout theincubation. The culture is held at this elevated temperature and underagitation until the titratable acidity goes beyond 0.55% and approaches0.80%. It is during this titratable acidity increase that the productionof diacetyl occurs. Compared with conventional processes which requirefrom 16 to 20 hours to develop a fully ripened culture, the presentprocess, in which the temperature is held in the high range until theacidity approaches 0.80% can be contemplated within from 8 to 12 hours.

By holding the culture at the desired high range of temperatures fordefinite periods oi time and until the titratable acidities indicatedare obtained, an unusually high yield of diacetyl is obtained. It isimportant that the high range of temperatures be employed, at leastuntil a titr'atable acidity of 0.55% of lactic acid is present. The timeof the entire process should not extend substantially beyond 12 hours.

While in the foregoing specification, I have set forth specific steps indetail for the purpose of illustrating specific embodiments of theinvention, it will be. understood that such details may be varied widelyby those skilled in the art without departing from the spirit of myinvention.

I claim:

1. In a process for the preparation of diacetyl. the steps ofinoculating milk with Streptococcus diacetylactis, and incubating themixture of a temperature of from -80 F. for a period less than 12 hoursand until at least a titratable acidity of about 0.55% lactic acid ispresent.

2. In a process for the preparation of diacetyl, the steps ofinoculating milk with Streptococcus diacetylactis, incubating the sameat a temperature of from Vii- F. for a period less than 12 hours anduntil a titratable acidity of about 0.80% is reached, and agitating themixture during incubation.

3. In a process-tor the preparation of diacetyl,

the steps or inoculating pasteurized skimmed milk with Streptococcusdiacetulactis, incubating the mixture at a temperature of about 75-80 F.for a period less than 12 hours and until a titratable acidity of 0.55%lactic acid is present, maintaining the temperature 01' about 68-70 F.until the titratable acidity reaches about 0.75-0.80%, and agitating themixture during incubation at a temperature of about (SB-70 F.

4. In a process for the preparation of diacetyl, the steps ofinoculating pasteurized skimmed milk with Streptococcus diacetylactis,maintaining the mixture at a temperature of from 75-80 F. for a periodless than 12 hours and until a titratable acidity of about 0.80% lacticacid is present, agitating the mixture during incubation, and thendiscontinuing the incubation treatment.

5. In a process for the preparation of diacetyl. the steps of addingStreptococcus diacetulactis to milk, incubating the mixture at atemperature of about 75-80 F. until a titratable acidity of about 0.55%lactic acid is present, and lowering the temperature to about 6870 F.until the titratable acidity reaches 0.75-0.80%.

MELVIN WAYNE MARCOUX.

4 REFERENCES CITED The following references are of record in the tileoi. this patent:

UNITED STATES PATENTS \Number Name OTHER REFERENCES Bergeys Manual (6ed.), 399.

Date

Werkman Apr. 9, 1940 of record, pages 325,

Bergey's Manual 01' Determinative Bacteriology,

3rd ed., 1930, p. 62.

Bergey's Manual of Determinative Bacteriology,

6th ed., 1948, pp. 325 and 339.

The Butter Industry by Hunziker, pages 327-331, 334 and 335.

1. IN A PROCESS FOR THE PREPARATION OF DIACETYL, THE STEPS OFINOCULATING MILK WITH STREPTOCOCCUS DIACETYLACTIS, AND INCUBATING THEMIXTURE OF A TEMPERATURE OF FROM 75-80* F. FOR A PERIOD LESS THAN 1IHOURS ADN UNTIL AT LEAST A TITRATABLE ACIDITY OF ABOUT 0.55% LACTIC ACIDIS PRESENT.